The present invention generally relates to solar panel installation, and more particularly relates to methods, apparatus, and systems for attaching a solar panel to an attachment support structure.
A solar (or photovoltaic) panel generally converts sunlight into solar electricity. Usually comprised of a semiconductor material, such as silicon, photons in sunlight hit the solar panel and knock loose electrons from their atoms, allowing them to flow through the material to produce electricity.
Referring now to FIGS. 1A-C, a set of drawings of a simplified solar panel is shown. FIG. 1A shows an isometric view of the simplified solar panel. FIG. 1B shows a side view of the simplified solar panel. FIG. 1C shows and underside view of the simplified solar panel.
Typically a relatively fragile photovoltaic substrate 102 is attached to a frame 104 for structural strength and protection, as well as providing a mechanism for attaching solar panel 100 to an attachment support structure (described below). Frame 104 generally includes a plurality of frame holes 106 through which a solar panel fastener (e.g., nuts, bolts, screws, etc.) may be inserted in order to secure the solar panel.
Consequently, since solar panel output power is directly proportional to the amount of sunlight exposure as well as operating temperature (output may vary by 2.5% for every 5 degrees variation in temperature), it is critical that solar panels be positioned properly.
However, the installation of solar panels is generally inefficient and very labor intensive, often consuming over 66% of the total installation cost. For example, most typical configurations involve mounting a set of solar panels on an attachment support structure that, in turn, may be secured on a roof, ground, or similar structure. Similar in concept to a child's Erector Set® toy, an attachment support structure is generally configured as a set of metal beams with regular holes for nuts, bolts, screws, that is assembled into a series of horizontal, vertical, and diagonal members.
Referring now to FIG. 2A, a simplified side view diagram of an attachment support structure and solar panel is shown. Solar panel 100 is generally positioned from about 5° to about 25° toward the sun in order to maximize sunlight exposure. In a common configuration, lateral support members 110 are made from Unistrut® or other suitable framing support members. A set of solar panel fasteners are then inserted through frame holes (not shown) in order to secure solar panel 100 to attachment support structure frame 112.
Typically made out of tube steel, attachment support structure frame 112 is generally rectangular in shape and provides suitable sub-structure for the attachment of lateral support members. Attachment support structure frame 112 is in turn secured to a set of footings 124 on surface 126 (e.g., rooftop, ground, etc.) by a series of vertical support members 114a-b, diagonal support members 116a-b, and horizontal support member 122.
Referring to FIG. 2B, a simplified isometric diagram of a Unistrut framing support member is shown. Used extensively in industrial and commercial construction markets, Unistrut generally requires a spring nut and bolt (not shown) connected to continuous slotted channel 132 with a set of holes 134.
However, although versatile, the use of Unistrut tends to be relatively expensive to use, often over $1 per foot. In addition, installation is problematic since the solar panel frame is generally attached to the attachment support structure (as shown is FIG. 2A) via holes that are positioned underneath the photovoltaic substrate.
For example, a first worker would generally position a solar panel on the attachment support structure, while a second worker would climb into the relatively confined space underneath the attachment support structure. For each solar panel frame hole, both workers must generally reposition the solar panel such that a solar panel fastener may be inserted through both the solar panel frame hole and the corresponding Unistrut hole. In addition, after the solar panel fastener is inserted, it generally must be tightened from underneath the solar panel at the correct torque setting in order to properly secure the solar panel without damage.
Consequently, it would be beneficial to use an optimized clip in order to quickly attach a solar panel to a frame in a cost-effective manner. It is in this context that embodiments of the invention arise.